1) Field of the Invention
The present invention relates to a process to sequester carbon from organic material and, more particularly, to a dry reforming process maximizing the carbon recovery. It also relates to new catalysts for carbon sequestration and dry reforming processes.
2) Description of the Prior Art
Synthesis gas is a mixture composed primarily of hydrogen and carbon monoxide. Synthesis gas is used either in pure hydrogen production, as a raw material in the chemical industry for the manufacture of market valuable products or as an energy vector. It can also be converted to a solid or liquid synthetic fuel or “synfuel”.
Steam reforming reactions are widely used for the production of hydrogen streams and synthesis gas for a number of processes such as ammonia, methanol and Fischer-Tropsh process for the synthesis of carbon-containing compounds such as higher hydrocarbons.
Dry reforming with CO2 is also a known process to produce or refine synthesis gas but there are so far no industrial applications due to the high endothermicity of reactions. For example, the reduction of carbon dioxide with methane is an endothermic reaction (ΔH298=+247 kJ·mol−1). At high temperatures, its favorable entropy change (ΔS298=+257 J·K−1·mol−1) makes it a favorable equilibrium, ΔG1050=−23 kJ·mol−1.CH4(g)+CO2(g)→2CO(g)+2H2(g)  (1)
During dry reforming, the CO is also partially converted into solid carbon through the reaction known as Boudouard reaction for CO disproportionation:2CO(g)→CO2(g)+C(s)  (2)
Several technical problems occur during dry reforming due to the carbon formation. Therefore, most prior art documents focus on processes, reactions and catalytic systems aiming at the reduction of the carbon deposition during dry reforming.
If the carbon formation is undesired from a process point of view, it is however advantageous from an environmental point of view since carbon dioxide is a greenhouse effect gas (GHG). The amount of carbon formed during dry reforming is reduced the release of carbon dioxide in atmosphere, reducing thereby the GHG emission.